As is known, in top-loaded washing machines, the drum has two doors fitted with spring-loaded hinges. When the closed doors are released, e.g. by pressing a button, springs push the doors open by rotating them radially; and, conversely, the open doors are pushed manually back into the closed position in opposition to the springs, which are thus reloaded elastically.
Since the doors would be opened fairly sharply, thus endangering the user, the opening movement must be damped by fitting the doors with decelerating devices.
Generally speaking, many applications, not only electric household appliances, but also automotive components (such as a glove compartment door), involve damping the movement of two members in relative motion—normally relative rotation but possibly also relative sliding motion.
Known decelerating devices normally comprise a rotor (e.g. in the form of a turbine), which rotates immersed in a viscous fluid inside a casing; and the rotor is secured to one of the rotating members, and the casing to the other. Though effective, this type of decelerating device is bulky, particularly radially, and in direct proportion to the amount of braking action required, and is therefore unsuitable for use in a hinge, particularly one of small radial dimensions as in the case of a top-loaded washing machine drum.
On the other hand, other known, more radially compact, decelerating devices simply comprise a rotating pin immersed in the viscous fluid, and therefore fail to generate a high braking torque.